1,574 research outputs found
Assessing Tauc plot slope quantification: ZnO thin films as a model system
No full textOne of the most frequently used methods for characterizing thin films is UV-Vis absorption. The near-edge region can be fitted to a simple expression where the intercept gives the band-gap and the fitting exponent identifies the electronic transition as direct or indirect. (See Tauc et al., Physica Status Solidi, 15, 627 (1966); naturally, these are usually called “Tauc” plots.) In earlier work, we found that direct band-gaps fitted using Tauc’s method can be quite accurate, to ~1%. (See Viezbicke et al., Physica Status Solidi, B252, 1700 (2015).) Still, slopes of these Tauc plots are less frequently quantified, even though the slopes are directly rooted in key band-structure parameters. In this study, we examine the reproducibility of Tauc plot slopes for ZnO as a model direct-gap material and compare these experimental values with the theoretically derived slope. In contrast to the band-gap accuracy, the experimental slope values varied by several orders of magnitude. The histogram of slope values was significantly more compact for Tauc plots exhibiting less Urbach tail contribution. In these cases, the Tauc slopes can provide an order-of-magnitude quantification of other key band characteristics such as carrier effective mass.Peer reviewe
Energy-efficient re-use of existing commercial buildings
No full textSpecial issue on historic preservation.Peer reviewe
Beyond Sputnik: U.S. science policy in the twenty-first century
No full textScience and technology are responsible for almost every advance in our modern quality of life. Yet science isn't just about laboratories, telescopes and particle accelerators. Public policy exerts a huge impact on how the scientific community conducts its work. Beyond Sputnik is a comprehensive survey of the field for use as an introductory textbook in courses and a reference guide for legislators, scientists, journalists, and advocates seeking to understand the science policy-making process. Detailed case studies---on topics from cloning and stem cell research to homeland security and science education---offer readers the opportunity to study real instances of policymaking at work. Authors and experts Homer A. Neal, Tobin L. Smith, and Jennifer B. McCormick propose practical ways to implement sound public policy in science and technology and highlight how these policies will guide the results of scientific discovery for years to come
Modeling dyadic effects in the associations between relational uncertainty, sexual communication, and sexual satisfaction for husbands and wives
No full textThis study models the individual and dyadic associations between relational uncertainty, indirect communication about sexual intimacy, and sexual satisfaction within marital relationships. A sample of 220 married couples completed questionnaires about their sexual relationship and hypotheses were tested using structural equation modeling. Results indicated that (a) relational uncertainty is positively associated with indirect communication about sexual intimacy for both husbands and wives, (b) indirect sexual communication is negatively associated with husbands’ and wives’ own sexual satisfaction, (c) husbands’ and wives’ sexual satisfaction and indirectness about sexual intimacy are positively associated, and (d) husbands’ and wives’ indirect communication about sexual intimacy are negatively associated with their spouse’s sexual satisfaction. The results are discussed in terms of their implications for understanding the dynamics of sexual intimacy within marriage.Peer reviewed
Relational turbulence in the post-deployment transition: Self, partner, and relationship focused turbulence
No full textThis study applied the relational turbulence model to the communication of U.S. service members and at-home partners following the return from a tour of duty by evaluating three turbulence markers: (a) relational maintenance, (b) partner responsiveness, and (c) turmoil appraisals. Participants were 235 individuals (128 service members, 107 at-home partners) who completed an online questionnaire within six months following reunion. Relational uncertainty and interference from partners predicted turbulence markers, and they partially mediated the association between relationship satisfaction and turbulence markers. Results suggest that the relational turbulence model is useful for illuminating the experiences of military couples during the post-deployment transition. Findings also point to turbulence markers that may be salient during a variety of relationship transitions.Peer reviewe
A Theme Analysis of Experiences Reported by Adult Children of Alcoholics in Online Support Forums
No full textGrowing up with an alcoholic parent can have a lasting effect on children and contribute to a variety of challenging outcomes in adulthood. This study identified the various experiences that adult children of alcoholics discuss with their peers in online support groups. Trained coders conducted a thematic analysis of 504 message board posts collected over a period of 60 days from three different online support groups to identify issues that children of alcoholics face in adulthood. Seven themes emerged from the analysis: a) empowerment through support, b) interference of parent in adulthood, c) connection to inner child and need to re-parent, d) low self-esteem and insecurity, e) anger and resentment, f) romantic relationship problems, and g) problems communicating. The results of this study provide insight into the issues that adult children of alcoholics need to address as part of their own recovery and suggest avenues of exploration for practitioners who work with high risk families.Peer reviewe
A Comparative Analysis of the Equity Outcomes in Three Sugarcane–Ethanol Systems
No full textThis article identifies equity outcomes associated with three biofuel systems in Brazil, Ethiopia, and Guatemala. Acknowledging that winners and losers are socially and politically generated, the article identifies some of the factors behind the distribution of winners and losers along different stages of three sugarcane–ethanol supply chains. Analyzing the outcomes for equity within each case study reveals an uneven distribution that, we argue, is related to the procedure and structure of the given sugarcane–ethanol system, and the recognition of the impacts on different actors within those structures. Increasing equity in sugarcane–ethanol systems will require greater openness in decision-making processes, in order that multiple voices are taken into account in the promotion, production, and consumption of biofuels—particularly those of smaller and less powerful actors
Partner Facilitation and Partner Interference in Individuals' Weight Loss Goals
No full textDrawing on the logic of the relational turbulence model, this study examined the ways in which romantic partners facilitate and interfere with individuals’ weight loss goals. Participants (N = 122) described the ways in which their romantic partner had recently helped or hindered their weight loss at four times over the course of 2 months. We conducted a content analysis of responses to identify themes of partner facilitation (Research Question 1 [RQ1]) and partner interference (RQ2) in individuals’ weight loss goals. Results revealed seven themes of partner facilitation: (a) partner enabling diet, (b) motivation and encouragement, (c) emotional support and positive reinforcement, (d) exercising together, (e) partner enabling exercise, (f) dieting together, and (g) relationship influence and priorities. Four themes of partner interference emerged in the data: (a) inability to plan for healthy meals, (b) inability to control the food environment, (c) preventing or discouraging exercise, and (d) emotional or relational discouragement.Peer reviewe
The interaction of fasting, caloric restriction, and diet-induced obesity with 17β-estradiol on the expression of KNDy neuropeptides and their receptors in the female mouse
No full textArcuate neurons that coexpress kisspeptin (Kiss1), neurokinin B (Tac2), and dynorphin (Pdyn) mediate negative feedback of 17β-estradiol (E2) on the HPG axis. Previous studies report that fasting and caloric restriction reduce arcuate Kiss1 expression. The objective of this study was to determine the interactions of E2 with fasting, caloric restriction, and diet-induced obesity on KNDy gene and receptor expression. Ovariectomized female mice were separated into control and estradiol benzoate (E2B)-treated groups. E2B decreased Kiss1 and the tachykinin 2 receptor, Tac3r, in ARC tissue and Tac2 in Tac2 neurons. Diet-induced obesity decreased Kiss1 in oil-treated animals and the kisspeptin receptor, Kiss1r and Tac3r in the ARC of E2B-treated animals. Chronic caloric (30%) restriction reduced all three neuropeptides in oil-treated females and Kiss1r by E2B in CR animals. Taken together, our experiments suggest that steroidal environment and energy state negatively regulate KNDy gene expression in both ARC and Tac2 neurons.Peer reviewe
Methods of increasing toughness of immiscible polymer blends, U.S. Patent 8,497,324
No full textAn immiscible polymer blend that includes an amount of poly(trimethylene terephthalate) (PTT) and an amount of poly(methylmethacrylate) (PMMA). A method for preparing an immiscible polymer blend by (a) identifying a first polymeric component and a second polymeric component as immiscible when blended; (b) combining the first polymeric component and the second polymeric component; and (c) mixing the first polymeric component and the second polymeric component to produce an immiscible polymer blend that includes structures in the blend having a maximum size of less than about 1,000 μm is also presented. An article that includes an immiscible polymer blend of poly(trimethylene terephthalate) (PTT) and poly(methylmethacrylate) (PMMA) and an article formed from an immiscible polymer blend prepared by the method of the present invention are also presented
- …
